1. Field of the Invention
The present invention relates to an aircraft door and, more particularly, to a door that is mounted to an access opening of a helicopter.
2. Description of Related Art
A helicopter generally includes a fuselage in which access openings are provided. These access openings are designed to enable people to board the helicopter and to load freight inside storage areas. Each access opening is equipped with a door, which essentially includes an outer skin attached to a framework. When the door is closed, the outer skin extends flush with the surrounding surface contour of the fuselage skin. Each door is conventionally secured to the fuselage by using a hinge mechanism in which the door is opened by being swung in an arc about its hinges. The procedure is reversed in order to close the door.
The cantilevered load that acts upon the hinge mechanism of a door when the door is opened may be significant due to the weight of the door and exposure to wind. Thus, the size of the access openings into which doors are mounted is generally limited. However, such size limitation may not be desirable for access openings arranged in the rear portion of a helicopter since they may be used to load freight or accommodate stretchers and emergency personnel during medi-vac operations. Thus, in order to increase the size of a rear access opening of a helicopter, two door panels are generally used. The door panels are configured as French doors and open towards the outside of the helicopter. Because two doors are used, they can be made smaller, and thereby lighter, than a single panel door.
Although a two-panel door may significantly minimize the load that acts upon the hinge mechanism of each panel, such a door remains heavy and its opening and closing may take longer and be more cumbersome. Specifically, each of the two panels must be handled one after the other and in precise order to carry out a closing that ensures proper closing and opening. In addition, such a door may be more difficult to seal due to the extra linear split at the centerline defined between the panels.